This fun Arduino project keeps track of how much you've exercised and, if you haven't put in enough time, reduces your computer's mouse speed to its slowest setting to keep you motivated.

The Personal Energy Orb—or PEO, for short—hooks up to your bicycle and keeps track of how much you've exercised. When you've biked enough, the orb turns from red to green. Hook it up to your computer and it'll let you use it without a problem. But, over time, the device will go back to red, and in turn will make your mouse pointer annoyingly slow, motivating you to get back out and exercise to recharge the orb. It's a clever—if not annoying—way to keep you active, and could be a good solution if you're particularly difficult to pull away from the screen. Check out the video above to see it in action, or hit the link below to see how to put one together. And if you've never used an Arduino before, we've got a guide on how to get started.